Release Process

Stable Glibc releases are further maintained in release branches, where they continue to receive backports of bugfixes committed to the main development branch (master). Thus, users will be able to get e.g. 2.16.1 with many bugfixes since fixed in mainline compared to the "main release" 2.16.

2. General policy

Each release branch owns a Git ref namespace release/VERSION/, recommended structure being release/VERSION/master for development, while tags are made under the common scheme glibc-VERSION.REVISION (i.e. glibc-2.11.1).

Normally, a release branch is forked off master after the stable version is tagged (usually, commits intended to update the version appear for few days after the version is tagged and the release branch would diverge only right before version.h is updated to reflect start of development for next main version), and consists purely or almost purely of cherry-picked fixes committed to the master branch.

Each branch is maintained by a single release manager, who has the responsibility of maintaining the particular stable branch, has final say on what goes in and tags further revisions on the branch. The branch is expected to receive many liberally merged bugfixes from master at the beginning when many new bugs are found, then become more conservative and decrease the rate of back-ports as most major problems are solved and the branch is being propagated to more mature distribution versions. Usually, the interested committers have discretion over which bugfixes to pick for back-porting, but if discussion arises, general consensus of the community is sought, the default choice being to err on the conservative side.

It is best if a release manager volunteers, and is agreed by the community, at the start of mainline development leading to the new release (for example, a 2.17 release manager should be agreed around the time 2.16 is released). If a release manager is agreed at that time, they may then agree a release timetable with the community for the next stable release and branch. If you would like to try this out, and especially if you have some interest in the branch well-being (e.g. you are distro maintainer who will base a distro branch on top of this release), feel free to just suggest yourself on libc-alpha!

Each branch has so-called interested parties, usually glibc maintainers in distributions where the particular branch is being used; tagging revisions on the release branches should result of consensus between the maintainer and interested parties - one workable model is that the maintainer suggests that he wants to release and other people check if they are happy with the set of patches included and the timing is fine-tuned; if a release is important for one of the parties (e.g. distribution nearing a release), they can suggest a release of new revision as well if it is meaningful.

Anyone can suggest a fix committed on master (unless it's N/A for master for some reason - in that case, discussion about the patch is expected) to be included in a release branch, either by marking it by an appropriate keyword in bugzilla, or cherry-picking it themselves and sending a pull request. Developers with glibc commit permissions can in general push into any release branch, but they are expected to execute reasonable judgement and follow the branch policies. All cherry-picked commits should be created using git cherry-pick -x to indicate the id of the original commit in the commit message (see details on cherry-picking in Git). Always aim at having one cherry-picked commit for one original commit.

Note that the above process is still in flux and may change based on our experience with it. Particular release branches may fine-tune these policies in different ways, though the spirit should stay the same. Try to pay attention to what your past (or concurrent) predecessor release managers have done, and learn from their examples and mistakes. It is expected to have discussion on new policies (even per-branch ones) and any unusualities on libc-alpha.

Final words: Always keep in mind the GNU copyright discipline.

3. New Release Manager

Each release manager should have or gradually obtain:

[REQUIRED] Push access to git.sourceware.org.

[REQUIRED] A published (preferably well cross-signed) PGP key for signing release tags.

[RECOMMENDED] Have your PGP key in the list of glibc releasers on gnu.org; see below.

[RECOMMENDED] Have full shell access to sourceware.org; see below.

4. Step-by-Step Release

Process

Full Release

Point Release

Development

New development

Backports

Freeze

News/Contrib

Translations

Testing

Regenerate

Final translations

Tag

Branch

Upload release

5. Release Steps

5.1. Development

Active development is carried out on master.

The release branches receive backports from master:

For every new point release e.g. X.Y.N create a new section in NEWS which will contain the new set of fixed bugs for the point release. Make sure that you add both the bugzilla number of the backport request and the original bugzilla issue fixed by the backport to the NEWS bug number list i.e. all bugs fixed should go into NEWS.

Work through the bugzilla issues tagged with the keyword associated with the release branch you maintain. For example if you are maintaining X.Y and a bug has the keyword glibc_X.Y, then that means the fix for this bug should be backported to glibc_X.Y. As the release manager you have two options, accept the change and carry out the backport or reject the change. If you reject backport you must remove the glibc_X.Y keyword and document in the issue why the bug was rejected for backport to glibc release branch X.Y.

5.2. Freeze

A general development freeze should be declared some time before release.

During this period before the release, the release manager may ask committers to limit commits to master. Changes to avoid include:

Anything requiring ports architecture maintainers to update their ports (the period should allow them to catch up with any updates left from the previous development).

Anything changing the public ABI and so requiring check-abi updates on each architecture, or adding libm tests that will require ulps updates on each architecture (again, the period allows for architecture maintainers to update these files and get them ready for the release).

Anything that subjectively seems too risky.

5.3. News

Shortly before the release, look for any significant user-visible changes not mentioned in the NEWS file and add them to that file.

5.4. Update manual/contrib.texi

Shortly before the release, check that the contributors for this releases are given credit in manual/contrib.texi.

5.5. Update manual/install.texi

Shortly before the release, test building with the most recent GCC release and update the statement in manual/install.texi about the most recent GCC release with which building glibc was tested. Similarly for binutils and texinfo. Regenerate the INSTALL file.

5.6. Translations

Some time before the release, regenerate libc.pot. See Regeneration for details.

If there are any new messages or changes to messages since the last libc.pot submitted to the Translation Project, generate a snapshot tarball. Distribute it from sourceware.org. Submit it to the Translation Project so translations can be updated before the release.

The step by step process is like this:

Regenerate libc.pot, review the changes and check it in.

Generate tarballs using make dist.

Upload snapshot to alpha.gnu.org using gnupload e.g. ./gnupload --to alpha.gnu.org:glibc glibc-2.20-546-ga8db092.tar.bz2 (Careful that absolute path to tarball is also appended on the remote host). Do not upload to ftp.gnu.org, only official releases should be uploaded there.

5.7. Testing

Architecture maintainers should test glibc for their architectures using the testsuite to make sure it is working well (the release manager should ask them to do so). libc architecture maintainers should update ABI baselines; see Regeneration. All architecture maintainers should update the ulps baselines for libm tests as needed; see Regeneration.

In an attempt to increase the quality of a release we run the following additional testsuites at this time:

5.8. Regenerate

After testing and shortly before the release (perhaps a week before) regenerate all files that need regeneration. See Regeneration. Please note that make dist-prepare is not sufficient for this use case since it should regenerate files even if the timestamps are up to date.

Ask the Web Admin Team to update the glibc homepage at gnu.org. The online manual there should also be updated.

Ask the Bugzilla Admin Team to update the sourceware bugzilla to add a new keyword to track this release e.g. glibc_M.N.

Ask the Bugzilla Admin Team to update the sourceware bugzilla to add a new version and milestone to track the next release e.g. M.N. Versions and milestones are best added when development starts for a release, not after branching (for example, create those for 2.17 at the time 2.16 branches), but if the newly branched version does not already have them, then they should be created at that time.

FROM: Release Manager <you@exmaple.com>
SUBJECT: The GNU C Library version X.Y is now available
The GNU C Library
=================
The GNU C Library version X.Y is now available.
The GNU C Library is used as *the* C library in the GNU system and
in GNU/Linux systems, as well as many other systems that use Linux
as the kernel.
The GNU C Library is primarily designed to be a portable
and high performance C library. It follows all relevant
standards including ISO C11 and POSIX.1-2008. It is also
internationalized and has one of the most complete
internationalization interfaces known.
The GNU C Library webpage is at http://www.gnu.org/software/libc/
Packages for the X.Y release may be downloaded from:
http://ftpmirror.gnu.org/libc/
http://ftp.gnu.org/gnu/libc/
The mirror list is at http://www.gnu.org/order/ftp.html
NEWS for version X.Y
====================
<Cut and paste from NEWS file>
Contributors
============
This release was made possible by the contributions of many people.
The maintainers are grateful to everyone who has contributed
changes or bug reports. These include:
<git shortlog --summary -w72 glibc-(Previous X.Y tag).. | sed -e 's,^.*\t,,g'>